Service Efficient Network Interconnection via Satellite: EU Cost Action 253 Edited by: Yim Fun Hu, Bradford Univ., UK, G. Maral, Ecole Nationale Superieure Des Telecommunications, France & Ferro, CNUCE/CNR , Italy Satellite Communications Systems - Systems, Techniques & Technology 4th Edition G. Maral, Ecole Nationale Superieure Des Telecommunications, France & M. Bousquet, Ecole Nationale Aeronautique et Espace, France Satellite Communication Systems, 3rd Edition Gerard Maral, Ecole Nationale Supérieure des Télécommunications, Toulouse, France and Michel Bousquet, Ecole Nationale Supérieure de l'Aeronautique et l'Espace, Toulouse, France VSAT Networks Gerard Maral, Ecole Nationale Supérieure des Télécommunications, Toulouse, France Mobile Satellite Communication Networks  Ray Edward Sheriff and Yim Fun Hu, both of University of Bradford, West Yorkshire, UK